fetch data as needed / typed dataset ( oracle fetch-size )

Hi,

I am working with dotNet 4.0 and ODP.NET ( Oracle data provider for .NET ). I need a mechanism to retrive some number of rows instead of the whole set. And when user "runs out of data" ( moves to some position near the end of the current dataset ), fetch another piece of the dataset.  It is a problem when 1000000 records is loaded into the datagrid. I know that oracle mantains an open cursor, and uses session's fetch size setting to calculate the ammount of rows it will send per trip. Is there any auto mechanism for it, or do i need to code it by hand. if I must code it, what would be the best approach?

Thank you!